Copying machine

ABSTRACT

A master pattern and a die blank rotate in the same direction at the same speed. A follower traverses the master pattern and is on a common support with cutting means for cutting the die blank. The master pattern support shaft is movable in an axial direction to permit the die blank to be cut with a concave or convex dome effect.

United States Patent [191 Coverdale, Jr.

[ Mar. 26, 1974 COPYING MACHINE James C. Coverdale, Jr., Chadds Ford,Pa.

Assignee: Franklin Mint Corporation,

Franklin Center, Pa.

Filed: Jan. 17, 1973 Appl. No.: 324,249

Inventor:

US. Cl. 90/13.7, 90/139 Int. Cl. B23c 1/18 Field of Search 90/l3.4,13.7, 13.9

References Cited UNITED STATES PATENTS Meyers 90/13.?

Primary Examiner-Francis S. Husar Attorney, Agent, or Firm--Seidel,Gonda & Goldhammer [57] ABSTRACT 10 Claims, 7 Drawing FiguresPAIENTEBmes an i 3799.028

SHEEI 1 0F 4 PAIENTED MR 26 1974 SHEEI 2 0F 4- A VN U QN\ NN\ WM 0 m M 3b o QM w Wm Q m Fl! N .$\L

PATENTED R26 I874 sum. 3 [IF 4 COPYING MACHINE This invention relates toa machine for copying a master pattern and reproducing the masterpattern on the end face of a die blank. In a typical embodiment of thepresent invention, the die blank is used for making coins in conjunctionwith a mating die blank.

Devices for reproducing the master pattern on the end face ofa die blankare known. For example, see U. S. Ser. No. 043,897 filed June 5, 1971,now US Pat. No. 3,719,121, and the file wrapper references therein. Thepresent invention enables the die blank to be made with a concave domeeffect, enables a dome effect to be added when the master is flat,enables the dome effect to be changed when the master is madeimproperly, etc. The dome effect is attained by a control means forshifting the shaft supporting the master in an axial direction.

It is an object of the present invention to provide a copying machinewhich will permit the application of a dome effect.

It is another object of the present invention to provide a copyingmachine for copying a master pattern on a reduced scale with a domeeffect.

It is another object of the present invention to provide a copyingmachine which permits a dome effect to be added or subtracted to themaster pattern.

It is another object of the present invention to provide a copyingmachine which will permit the application of a dome effect with avariety of different curvatures.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in thedrawings a form which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1 is a partial perspective view of a copying machine in accordancewith the present invention with most of the frame being deleted forclarity of illustration.

FIG. 2 is a front elevation view of the machine shown in FIG. 1.

FIG. 3 is a sectional view taken along the line 33 in FIG. 2.

FIG. 4 is a sectional view taken along the line 44 in FIG. 3.

FIG. 5 is a schematic layout of the drive shafts and gears.

FIG. 6 is a sectional view of a master pattern having a convex domeeffect.

FIG. 7 is a sectional view of a die blank having a similar convex domeeffect.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is shown in FIG. 1 a copying machine in accordance withthe present invention designated generally as 10. In FIG. 1, most of theframe has been deleted for clarity of illustration.

A master pattern 12 is removably bolted to a mounting plate 14 which isremovably attached in any convenient manner such as by threads to oneend of a drive shaft 16. As shown more clearly in FIG. 3, the shaft 16is rotatably supported by bearings 18 and 18 in the frame 20.

In FIG. 3, the shaft 16 is biased from left to right. The bias ispreferably accomplished by means of a spring 22 which surrounds theshaft 16 and engages a collar 24. Collar 24 is adjustably positionedalong the shaft 16 and removably connected thereto in any convenientmanner such as by means of a set screw.

The shaft 16 includes splines 26 coupled to a gear 28 which surroundsthe shaft 16. Gear 28 is in meshing engagement with a worm gear 30 onshaft 32. See FIG. I. A similar worm gear 34 on shaft 32 is meshed witha gear 36 connected to shaft 38. The shaft 38 is similarly supported bythe frame 20. A mounting plate 42 on one end of shaft 38 has a die blank40 removably attached thereto in any convenient manner. The die blank 40has an exposed end face which is to be cut by means of a cutting tool48. Cutting tool 48 is supported by an arm 46. A stylus 44 is likewisesupported by the arm 46. Each of the cutting tool 48 and stylus 44 areadjustably positioned along the arm 46 in any convenient manner such asby use of a set screw. Arm 46 has its left end portion supported by auniversal joint 52 whereby arm 46 may move about vertical and horizontalaxes.

The cutting tool 48 is attached to a shaft which in turn is connected toa pulley 50. As shown more clearly in FIG. 2, pulley 50 is connected bymeans of a belt 54 to a pulley 56. Pulley 56 is connected to the outputof a motor 58. Motor 58 is supported in any convenient location on theframe 20. Belt 54 is tensioned in any convenient manner such as by aspring-biased idler as shown in FIG. 2.

As shown more clearly in FIG. 1, the end of the arm 46 remote from theuniversal joint 52 is supported by a means designated generally as 60for pivoting arm 46 about a horizontal axis in a controlled manner. Themeans 60 includes a weight 62 sized to balance or otherwise obtain thedesired effective weight of arm 46. Weight 62 is connected to one end ofa flexible member 64. Member 64 extends around pulleys 66 and 68 onplate 70. Plate 70 is secured to a stationary vertical standard 71.

From the pulley 68, the flexible member 64 extends downwardly and isconnected to pin 72. Thereafter, the flexible member 64 extendshorizontally around pulley 74 and then upwardly around pulley 76. Thefree end of the flexible member 64 is connected to a weight 78 which issized so as to control the pressure of the stylus 44 against the masterpattern 12.

A drive screw 80 moves a slide 82 in an up and down direction dependingupon the direction of rotation. Pulley 74 is supported by the slide 82.A roller 84 on the slide 82 extends into the jaw 87 at the righthand endof arm 46 as shown more clearly in FIG. 1 and is in contact with aroller 86 which is perpendicular thereto. Pin 72 is secured to the jaw87.

As shown more clearly in FIGS. 3 and 4, the means for shifting themaster pattern 12 to provide the dome effect includes a stationaryupright standard 88 having upright ways 90. A slide 92 is engaged withthe ways and moved in an up and down direction by the screw drive 94. Ahand wheel 96 is connected to the upper end of the screw drive 94. Asimilar hand wheel is connected to one end of the screw drive 80.

A cantilever beam 98 is adjustably connected to the slide 92 at itsupper end by means of clamp 100. I-Iorizontal deflection of beam 98 intoand out of the plane of the paper is prevented by guide bracket II3. SeeFIG. 3. Slide 92 is provided with a way 102. A slide 104 is inengagement with and movable along way 102. An indicator 106 having anindicating pin 108 is mounted on the slide 104. Pin 108 engages the beam98 and the amount of deflection is exhibited on the indicator 106.

A pressure applicator 110 is supported by the slide 104. Applicator 110may be in the form of a threaded member having a head 112 at one endwith its other end engaging the beam 98. Applicator 110 deflects thebeam so that it may act as a cam.

Referring to FIG. 5, a motor 114 is provided for driving the variousshafts and screw drives. Motor 114 has its output connected by way of abelt or chain 116 to drive shaft 118. Shaft 118 is connected to parallelshaft 122 by means of a belt 120 which extends around coneshapedportions on the shafts 118 and 122.

Shaft 122 is coupled to shaft 32 by means of a belt 124. Shaft 122 isconnected to the input side of a speed reducer 128 by means of belt 126.The output from the speed reducer 128 is connected to upright shaft 130.Shaft 136 is driven by meshing engagement between the beveled gears 132and 134. Shaft 136 is connected to worm gear 136 which is in drivingengagement with the screw drive 94.

Shaft 130 also drives shaft 146 by way of the meshing bevel gears 142and 144. A worm gear 148 on shaft 146 is in meshing engagement withscrew drive 80. A set of matching worm gears exists for accomplishingfeed rate changes on feed screws 80 and 94. Thus, identical worm gearsare placed on both shafts. The interchangeable gears also accomplish thedirectional change in rotation.

In operation, the stylus 44 is positioned at the center of the masterpattern 12. On some jobs the stylus may initially be positioned on theouter periphery and run toward the center. The cutting tool 48 issimilarly at the center of the die blank 40. Speeds are chosen so thatthe die blank 12 revolves at a slow speed such as 1 rpm. The speedreducer 28 and the various gear drives to the screw drive 80 are chosenso that the means 60 for pivoting the arm 46 will cause the arm to pivotthrough an arc at a slow steady speed whereby the stylus 44 willtraverse the radius of the master pattern over a substantial period oftime such as four to sixteen hours depending upon the radius of themaster pattern and the feed rate selected.

As the stylus 44 follows the contour of the master pattern 12, thecutting tool 48 reproduces the contour on the end of the die face 40. InFIGS. 6 and 7, there is shown a sectional view of the master pattern 12and the die blank 40, each provided with a convex dome effeet. Theamount of the dome is designated as X. On coining dies, the amount ofthe dome is generally not more than 0.150 inch.

In FIG. 3, a zero or null point on the beam 98 is in contact with therounded end of the shaft 16. The slide 104 has been moved to a positionso that the pin 108 for the indicator 106 is spaced from the axis ofshaft 16 by a distance correspondingto a radius of the master pattern asmeasured by the expanded scale 200 (shown in FIG. 2). Head 112 isrotated in an appropriate direction to bend the beam 98 until thedesired amount of dome is indicated on indicator 106. As the stylus 44traverse the radius of the master pattern, the slide 92 is raised at thesame rate so that beam 98 moves up wardly. When the stylus 44 hasreached the outer periphery of the master pattern 12, pin 108 will bedirectly opposite the longitudinal axis of shaft 16.

As the beam 98 is raised upwardly, it causes the shaft 16 to move in anaxial direction along its axis of rotation from right to left in FIG. 3.In doing so, the spring 22 is compressed. If a concave dome effect isdesired,

it is only necessary to raise the entire slide 104 until the pin 108 iscoaxial with shaft 16 and then cause'the slide 104 to descend. Slide 104may be caused to descend by substituting a different worm gear in placeof worm gear 138. Thus, as the beam 108 descends the spring 22 wouldgradually move the shaft 16 from left to right in FIG. 3.

The beam 98, whether it moves upwardly or downwardly, moves at the samespeed that the stylus moves in a radial direction in respect to a masterpattern. Thus, at the end of the travel of the beam 98, the stylus 44will be at the end of its travel.

The cutting tool 44 is closer to the pivot axis of the universal joint52 as compared with the stylus 44. If the arm 46 pivots about a verticalaxis through an arc of 5, the stylus 44 will move through a greaterdistance than the cutting tool 48. The difference in the amount ofmovement between the stylus 44 and the cutting tool 48 is a function oftheir distances from the pivotable axis for the arm 46. These distancesare mathematically computable using trigonometry and determine thereduction ratio between the master model and the die hub being cut.

The stylus 44 is displaced by the horizontal distance D from the pin 84,which is effecting the vertical rate of speed of arm 46. Since thesupport arm 46 moves in an arc about the universal joint 52, there is adifference in the vertical displacement of the slides 82, 92, eventhough both feed screws 80, 94 have the same lead and are being rotatedwith identical RPM. This difference in vertical displacement is afunction of the arc lengths traveled by the stylus 44 and the point ofcontact between the feed pin 84 and the support arm roller 86. Thisdifference in vertical displacement is taken into account by means of anexpanded scale 200 mounted in any convenient place on the slide 92.

The expanded scale 200 permits the operator of the machine to set thedisplacement of the indicator pin 108 with respect to the axis of shaft16 at the same numerical value in inches as the radius of the masterpattern 12. However, due to the scale expansion, the actual displacementof the pin 108 is equivalent to the distance traveled by the point ofcontact between pin 84 and roller 86. Since both feed screws 80, 94 haveidentical lead and are rotated in synchronization, the stylus 44 willterminate at the outer periphery of the master pattern 12 at the sametime pin 108 is coaxial with shaft 16. Other equivalent devices may beutilized to accomplish the same result.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention. 8

I claim:

1. Apparatus for cutting a die comprising a frame, first shaft means onthe frame for supporting and rotating a master pattern, second shaftmeans on the frame for supporting and rotating a die blank in the samedirection and at the same speed as the master pattern, means on theframe for traversing a master on the first shaft means and for cutting adie blank on the second shaft means to reproduce the contour of themaster, means supporting said first shaft means for axial movement alongits axis of rotation, and shifting means for shifting said first shaftmeans in an axial direction along its longitudinal axis to create adesired dome effect on the cut die blank.

2. Apparatus in accordance with claim 1 wherein said shifting means is acam.

3. Apparatus in accordance with claim 2 wherein said cam is a cantileverbeam mounted for movement in a direction perpendicular to thelongitudinal axis of said first shaft means, and means for deflectingsaid beam.

4. Apparatus in accordance with claim 3 including biasing means forbiasing said first shaft means towards said beam.

5. Apparatus in accordance with claim 1 wherein said first and secondshaft means includes horizontal parallel shafts, said means fortraversing the master including a stylus mounted on a common supportwith the means for cutting the die blank end face, one end of saidcommon support being connected to a universal joint so that the commonsupport may move about a vertical and a horizontal axis, a first motorfor driving said first and second shaft means, and a second motor fordriving said cutting tool.

6. Apparatus in accordance with claim 1 wherein said shifting meansincludes a slide mounted on ways for movement in a directionperpendicular to the direction of the longitudinal axis of said firstshaft means, a screw drive for said slide, gear means coupling saidscrew drive to a motor, and gear means coupling said motor to said firstand second shaft means.

7. Apparatus in accordance with claim 6 wherein said shifting meansincludes a cantilever beam supported by the slide above and below thelongitudinal axis of said first shaft means whereby the dome effect maybe concave or convex.

8. Apparatus for cutting a die comprising means for supporting androtating a die about a horizontal axis, means for supporting androtating a master pattern about a horizontal axis and including a shaft,cam means for shifting the shaft along its longitudinal axis in timedrelationship to a follower for following the contour of the master alonga radius of the master as the master is rotating, and means connectingsaid follower to a cutting tool for cutting the die end face.

9. Apparatus in accordance with claim 8 wherein said cam means includesa cantilever beam which is perpendicular to the longitudinal axis ofsaid shaft, means for deflecting the cantilever beam, saidlast-mentioned means and said cantilever beam being mounted on a commonsupport for movement in a direction perpendicular to the longitudinalaxis of said shaft.

10. Apparatus in accordance with claim 9 including a screw drive formoving said last-mentioned common support.

1. Apparatus for cutting a die comprising a frame, first shaft means onthe frame for supporting and rotating a master pattern, second shaftmeans on the frame for supporting and rotating a die blank in the samedirection and at the same speed as the master pattern, means on theframe for traversing a master on the first shaft means and for cutting adie blank on the second shaft means to reproduce the contour of themaster, means supporting said first shaft means for axial movement alongits axis of rotation, and shifting means for shifting said first shaftmeans in an axial direction along its longitudinal axis to create adesired dome effect on the cut die blank.
 2. Apparatus in accordancewith claim 1 wherein said shifting means is a cam.
 3. Apparatus inaccordance with claim 2 wherein said cam is a cantilever beam mountedfor movement in a direction perpendicular to the longitudinal axis ofsaid first shaft means, and means for deflecting said beam.
 4. Apparatusin accordance with claim 3 including biasing means for biasing saidfirst shaft means towards said beam.
 5. Apparatus in accordance withclaim 1 wherein said first and second shaft means includes horizontalparallel shafts, said means for traversing the master including a stylusmounted on a common support with the means for cutting the die blank endface, one end of said common support being connected to a universaljoint so that the common support may move about a vertical and ahorizontal axis, a first motor for driving said first and second shaftmeans, and a second motor for driving said cutting tool.
 6. Apparatus inaccordance with claim 1 wherein said shifting means includes a slidemounted on ways for movement in a direction perpendicular to thedirection of the longitudinal axis of said first shaft means, a screwdrive for said slide, gear means coupling said screw drive to a motor,and gear means coupling said motor to said first and second shaft means.7. Apparatus in accordance with claim 6 wherein said shifting meansincludes a cantilever beam supported by the slide above and below thelongitudinal axis of said first shaft means whereby the dome effect maybe concave or convex.
 8. Apparatus for cutting a die comprising meansfor Supporting and rotating a die about a horizontal axis, means forsupporting and rotating a master pattern about a horizontal axis andincluding a shaft, cam means for shifting the shaft along itslongitudinal axis in timed relationship to a follower for following thecontour of the master along a radius of the master as the master isrotating, and means connecting said follower to a cutting tool forcutting the die end face.
 9. Apparatus in accordance with claim 8wherein said cam means includes a cantilever beam which is perpendicularto the longitudinal axis of said shaft, means for deflecting thecantilever beam, said last-mentioned means and said cantilever beambeing mounted on a common support for movement in a directionperpendicular to the longitudinal axis of said shaft.
 10. Apparatus inaccordance with claim 9 including a screw drive for moving saidlast-mentioned common support.